Findtime MCP Server

@findtime/mcp-server

@findtime/mcp-server is a thin stdio MCP wrapper over the production findtime.io Time API at https://time-api.findtime.io.

The package intentionally proxies the production API instead of re-implementing time logic locally. Current time, DST, conversion, overlap, meeting search, and location resolution should stay aligned with the live API.

Published surfaces:

• npm: @findtime/mcp-server
• GitHub: https://github.com/hkchao/findtime-mcp-server
• Official MCP Registry: https://registry.modelcontextprotocol.io/?q=io.github.hkchao%2Ffindtime-mcp-server
• MCP Registry name: io.github.hkchao/findtime-mcp-server
• Hosted server: https://mcp.findtime.io/mcp (Streamable HTTP, OAuth sign-in). It includes the time tools and saved teams. Booking tools (request, reschedule and cancel bookings; host approve/decline; booking pages and invite links) are available after you sign in with Google through the connector and grant the booking scopes. See Hosted server scopes for which OAuth scope covers which tool. The npm package covers the time and meeting-planning tools only and needs FINDTIME_TIME_API_KEY. It has no saved-group or booking tools: those need a findtime account signed in with Google on the hosted server, and an API key never gets booking tools.

Hosted server scopes

The hosted server's OAuth metadata (/.well-known/oauth-protected-resource and /.well-known/oauth-authorization-server) lists only the two default scopes, time:read and meetings:plan. A client that connects without naming a scope gets both. The booking scopes, booking:request and booking:host, are left out of scopes_supported on purpose, so a client that copies that list on first connect never asks for host access. They are still granted when a client asks for them by name.

When a signed-in client calls a booking tool without the scope it needs, the server answers 403 with WWW-Authenticate: Bearer error="insufficient_scope", scope="...". The scope value is the full set to ask for on the next sign-in. Asking for booking:host shows a findtime consent screen before Google sign-in.

The findtime booking API checks booking:request and booking:host again on its side, using a signed assertion from the hosted server. Those tools also need the person signed in to findtime with Google and a verified email. Finding a host's open times needs no booking scope. A Time API key (ftk_live_...) used as a bearer token gets time:read meetings:plan only and never sees the booking tools.

Tool surface

The npm package (stdio, API key) and the hosted server both have:

• answer_time_question
• get_findtime_help
• get_api_diagnostics
• send_feedback (reports a wrong answer; sends the tool name, never the query text)
• time_snapshot
• get_current_time
• get_dst_schedule
• convert_time
• get_overlap_hours
• find_meeting_time
• check_proposed_time (/meeting/check: verdicts for a time the user already picked)
• are_they_awake (/meeting/awake: work, awake, or sleep in other cities at one moment)
• rank_recurring_slot (/meeting/recurring: who a weekly time punishes, plus a kinder slot)
• search_timezones
• get_location_by_id

Hosted server only (https://mcp.findtime.io/mcp, signed in with Google). These are not in the npm package and never will be on an API key:

• Saved groups: save_team, get_team, list_teams, rename_team, delete_team. They read and write the homepage planner Saved groups of the signed-in Google account. On the npm package, a teamId without locations answers teams_not_persisted; pass locations on each call.
• Booking: get_host_booking_profile, find_host_slots, request_booking, get_booking_status, list_my_booking_requests, cancel_booking, reschedule_booking, get_my_booking_page, list_booking_requests, approve_booking_request, decline_booking_request, cancel_booking_as_host, update_booking_page, create_invite_link, revoke_invite_link. Every booking write returns a read-back first and changes nothing until it is called again with confirm: true; the host approves or declines every request.

Scopes for each hosted tool are in Hosted server scopes. Tool and setup docs: https://findtime.io/developers/mcp/#booking-tools. The booking routes these tools call: https://findtime.io/developers/#booking-api.

Prefer answer_time_question for messy natural-language prompts such as "3pm PST to London", "what is the IANA timezone for San Francisco?", "working hours overlap for SF, Berlin, and Tokyo", or "what does CST mean?". The tool classifies the prompt through findtime.io's domain logic, dispatches to deterministic Time API behavior, and returns structured ambiguity or clarification when the world is genuinely ambiguous.

Install in MCP clients

Use the published package through npx:

npx -y @findtime/mcp-server

For agent authors, include SKILL.md alongside the MCP config. It gives Claude, Codex, Cursor, Cline, Windsurf, custom company bots, and other LLM agents the operating rules for when to prefer findtime.io MCP, which tools to call, and how to handle ambiguity or fallback.

Required runtime:

• Node 20+
• FINDTIME_TIME_API_KEY: a valid findtime.io developer key from https://findtime.io/developers/keys/

Optional environment variables:

• FINDTIME_TIME_API_BASE_URL
• TIME_API_BASE_URL
• TIME_API_TIMEOUT_MS
• FINDTIME_BINDING_TYPE for optional install/workspace binding context. Supported values: slack_team, workspace_id, install_id.
• FINDTIME_BINDING_VALUE for the install/workspace identifier that matches the selected binding type.
• FINDTIME_BINDING_HEADER to override the header name directly for custom enterprise environments.
• FINDTIME_MCP_CLIENT_ID or FINDTIME_MCP_INSTALL_ID to provide a stable client identifier. If omitted, the server creates one locally under the user's state directory. When present, the MCP wrapper forwards it to time-api as X-Findtime-User-ID for enterprise usage attribution.
• FINDTIME_MCP_CLIENT_TYPE
• FINDTIME_MCP_TOOL_MODE=answer-only to expose only answer_time_question, get_findtime_help, and get_api_diagnostics for enterprise bots that should route every natural-language request through the answer API.
• FINDTIME_MCP_INSTRUMENTATION_ENABLED=false to opt out of anonymous usage telemetry.
• FINDTIME_MCP_USAGE_TELEMETRY_URL to override the default telemetry endpoint.

Per-call end-user attribution

Multi-user MCP hosts such as Slack, Discord, and Teams bots can run one long-lived @findtime/mcp-server subprocess while still attributing each Time API call to the end-user who triggered it. Add an optional _endUserId field inside the MCP tool call arguments object. The server strips _endUserId from the tool parameters and forwards it only as the upstream X-Findtime-End-User-ID HTTP header.

await client.callTool({
  name: "get_current_time",
  arguments: {
    city: "Tokyo",
    _endUserId: "a3f2c1d4e5b6c7d8"
  }
});

The field is optional and backward-compatible. If _endUserId is missing, null, or an empty string, the header is omitted and attribution falls back to the install-level FINDTIME_MCP_CLIENT_ID or FINDTIME_MCP_INSTALL_ID behavior.

Privacy contract: _endUserId must be an opaque token supplied by the MCP host, typically a SHA-256 hash of the platform user ID truncated to 16-32 hex characters. Do not send raw email addresses, names, Slack/Discord/Teams IDs, or other PII. Avoiding PII in this field is the host application's responsibility.

The server validates _endUserId defensively: it must be a string, at most 256 characters, and must not contain CR, LF, or other control characters. The raw value is never logged by the server.

Cursor

{
  "mcpServers": {
    "findtime": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@findtime/mcp-server"],
      "env": {
        "FINDTIME_MCP_CLIENT_TYPE": "cursor",
        "FINDTIME_TIME_API_BASE_URL": "https://time-api.findtime.io",
        "FINDTIME_TIME_API_KEY": "YOUR_FINDTIME_SECRET_KEY"
      }
    }
  }
}

Codex

[mcp_servers.findtime]
command = "npx"
args = ["-y", "@findtime/mcp-server"]
enabled = true

[mcp_servers.findtime.env]
FINDTIME_MCP_CLIENT_TYPE = "codex"
FINDTIME_TIME_API_BASE_URL = "https://time-api.findtime.io"
FINDTIME_TIME_API_KEY = "YOUR_FINDTIME_SECRET_KEY"
# Optional enterprise install binding:
# FINDTIME_BINDING_TYPE = "workspace_id"
# FINDTIME_BINDING_VALUE = "YOUR_WORKSPACE_ID"

Claude Desktop

{
  "preferences": {
    "...": "keep your existing preferences here"
  },
  "mcpServers": {
    "findtime": {
      "command": "npx",
      "args": ["-y", "@findtime/mcp-server"],
        "env": {
          "FINDTIME_TIME_API_BASE_URL": "https://time-api.findtime.io",
          "FINDTIME_TIME_API_KEY": "YOUR_FINDTIME_SECRET_KEY"
        }
      }
    }
  }

Claude CLI / Claude Code

Add findtime.io with:

claude mcp add --transport stdio \
  --env FINDTIME_TIME_API_BASE_URL=https://time-api.findtime.io \
  --env FINDTIME_TIME_API_KEY=YOUR_FINDTIME_SECRET_KEY \
  --env FINDTIME_MCP_CLIENT_TYPE=claude-cli \
  findtime -- npx -y @findtime/mcp-server

If your Claude CLI uses JSON config instead, add:

{
  "mcpServers": {
    "findtime": {
      "command": "npx",
      "args": ["-y", "@findtime/mcp-server"],
      "env": {
        "FINDTIME_TIME_API_BASE_URL": "https://time-api.findtime.io",
        "FINDTIME_TIME_API_KEY": "YOUR_FINDTIME_SECRET_KEY",
        "FINDTIME_MCP_CLIENT_TYPE": "claude-cli"
      }
    }
  }
}

For enterprise installs, the minimum credential is always the API key. If the install environment has a stable workspace or installation identifier, optionally add:

FINDTIME_BINDING_TYPE=workspace_id
FINDTIME_BINDING_VALUE=YOUR_WORKSPACE_ID

For Slack-specific installs:

FINDTIME_BINDING_TYPE=slack_team
FINDTIME_BINDING_VALUE=T01ABC123

Verify installation

Use an explicit tool-call prompt first:

Use the findtime.io MCP tool get_api_diagnostics.

Then:

Use the findtime.io MCP tool get_current_time for city "Tokyo" with countryCode "JP".

After that succeeds, switch back to normal natural-language prompts:

Best meeting time between New York, Sydney, and Mumbai?

Local development

Run the workspace version directly:

npm run mcp:start

The server attempts to load .env.development.local, .env.development, .env.local, and .env from:

• the current working directory
• services/mcp-server
• the repo root

Tests

Protocol and transport tests:

npm run test:mcp-server

Live production-parity smoke tests:

npm run test:mcp-server:smoke

The smoke suite checks:

• search_timezones
• answer_time_question
• get_current_time
• get_dst_schedule
• convert_time
• get_overlap_hours
• find_meeting_time
• get_location_by_id

Maintainer release flow

The canonical public source for this package now lives in:

• GitHub: https://github.com/hkchao/findtime-mcp-server
• npm: @findtime/mcp-server
• Official MCP Registry: https://registry.modelcontextprotocol.io/?q=io.github.hkchao%2Ffindtime-mcp-server

Publish and version updates should happen from that public repo, not from this private app repo.

Releases publish from CI when a v<version> tag is pushed: .github/workflows/publish.yml publishes to npm with trusted publishing (GitHub OIDC), then calls .github/workflows/publish-mcp-registry.yml to publish server.json to the MCP Registry. The full runbook (manual dispatch, re-runs, error fixes, and the hand-publish fallback) is the "Maintainer Release Playbook" in SKILL.md.

Standard release flow in the public repo, after bumping package.json and server.json and merging to main:

npm run release:check
npm test
npm pack --dry-run
git tag v<version> <merge-commit-sha>
git push origin v<version>

Hand publishing is a fallback only. prepublishOnly rejects it unless you set the acknowledgement that release:check prints:

FINDTIME_MCP_RELEASE_CHECKED=<version> npm publish --access public

The equivalent local verification checks in this repo are:

npm run test:mcp-server
npm run mcp:pack

Treat this repo as the implementation source that originally produced the MCP package, not as the canonical public release source.

Publisher and tool safety

The npm package @findtime/mcp-server and GitHub repository hkchao/findtime-mcp-server are the findtime.io MCP distribution channels. Product documentation: https://findtime.io/developers/mcp/

The npm package's tools query time information, suggest meeting times, or return help and diagnostics; they do not book meetings or modify calendars. They declare readOnlyHint: true, destructiveHint: false, idempotentHint: true, and openWorldHint: true, except send_feedback, which records a report and declares readOnlyHint: false, destructiveHint: false, and idempotentHint: false. Read-only describes the user-facing operation, not an absence of network traffic: API requests, diagnostics, and optional usage telemetry contact external services. Repeating a current-time query can return a new time; idempotent describes the absence of additional domain mutations.

The hosted server at https://mcp.findtime.io/mcp also has booking tools that do write: requesting, rescheduling, approving, declining, and cancelling bookings, changing a booking page, and making or revoking invite links. Approving or cancelling a meeting changes the host's Google Calendar. Those tools declare readOnlyHint: false, and the ones that cancel, decline, or revoke declare destructiveHint: true. They are not part of this package.

API-key environment variables are alternative configuration names for one key, not four separate credentials.

Privacy, authentication, and service limits

Privacy policy: https://findtime.io/privacy/

The stdio process runs locally. Time tools send their query arguments to the configured Time API (by default https://time-api.findtime.io). The selected API key is sent in the Authorization: Bearer header to that API, not to npm or telemetry. Configure only API hosts you trust. The four API-key variable names are aliases: the first nonempty value wins in this order: FINDTIME_API_KEY, TIME_API_KEY, FINDTIME_MCP_API_KEY, FINDTIME_TIME_API_KEY.

The hosted Time API owns API-key validation, configured per-key rate limits, and quotas. The wrapper forwards upstream failures, including HTTP 429, as MCP tool errors. It does not expose a public HTTP listener or implement a separate local rate limiter. Help is local; diagnostics also reads npm version metadata.

send_feedback posts only the tool name to /mcp/feedback on the configured Time API. It never sends the query text or whatWasWrong. The result reports the server's answer: 202 means recorded, 204 means findtime.io received the report but did not keep it (not an error, nothing to retry), and any other 2xx means accepted. Other statuses are error results.

Optional usage telemetry goes to https://slack.findtime.io/telemetry/usage by default. The wrapper sends tool name, outcome, query-text length, a persistent installation/client identifier, version, OS, locale, timezone, and latency. This telemetry event does not include raw query text, API keys, or the per-call _endUserId. Set FINDTIME_MCP_INSTRUMENTATION_ENABLED=false to disable it. A generated installation identifier is stored in the user's state directory. Host-provided attribution identifiers are sent to the Time API as documented above; use opaque non-PII values.

License

The MCP wrapper and documentation in this repository are licensed under the MIT License.

This license covers this repository only. It does not grant rights to the hosted findtime.io Time API, its backend implementation or data, or the broader findtime.io application. Use of hosted services remains subject to their applicable terms and API access requirements.